Remote terminal unit

ABSTRACT

A meter useful in measuring flow, such as electrical, gas, and water flow, where the meter includes a rotating wheel with markings that rotates in response to the flow sensed by the meter. The meter further includes an illumination source directing light to the surface of the rotating wheel, where a portion of the light is absorbed by the markings, and a portion of the light is reflected by the remaining surface of the rotating wheel. A detector array is included that reads the reflections and converts the readings into a signal. The signal can be analyzed in order to ascertain the rate and amount of flow sensed by the meter.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates generally to the field of flow metering. Morespecifically, the present invention relates to a device and method thatis capable of metering and measuring the flow of electrical, water, orgas flow.

2. Description of Related Art

Typically end users of utilities such as electricity, water, and gas,are equipped with meters at the point of supply. Where the point ofsupply is usually a residence or a business. The general principle ofthese flow meters is that the flow (either electrical, gas, or water) isused to produce a rotation or movement of a member, where the rotatingor moving member is mechanically connected with indicator dials thatrecord the usage of the utility by measuring its total flow.

While these indicator dials are capable of substantially reflecting theusage of the utilities, they must be visually accessed periodically inorder for the supplier of the utility to record the measured total flow.Conducting visual access by actual individuals presents additionalproblems, such as cost, time, and concern for the safety of theindividual meter readers. Accordingly telemetry processes have beendeveloped that can transmit flow usage data either directly to theutility provider or to a central location where retrieval of the data isless time consuming and safer.

One such device includes a photocell within the flow meter, where theflow meter includes a rotating wheel that rotates in response to theflow of electricity sensed by the meter. The wheel further includes amark on a portion of the wheel, where the photocell is able to recordthe presence of the mark based on the amount of light absorbed by themark in contrast to the light reflected by the wheel. Tracking themovement of the mark in turn monitors the number of rotations of thewheel that can then be evaluated to determine the usage of electricitysensed by the meter. However, the photocell can be disabled if anexternal light source is directed at it that mutes the distinctionbetween the light reflecting and light absorbing portions of the wheel'ssurface. Moreover, the photocell is a single light recording source, andis unable to distinguish the rotational direction of the wheel. It isimportant to know the directional rotation of the wheel sincemanipulating the meter to cause the wheel to rotate backwards can causethe flow measured by the meter to be less than the actual amount of flowthat has passed through the meter. Therefore, there exists a need for aflow metering system that is reliable, is able to detect tampering, andenhances accurate meter readings.

BRIEF SUMMARY OF THE INVENTION

The present invention.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 depicts a perspective view of a prior art device.

FIG. 2 illustrates a perspective view of a rotating wheel.

FIG. 3 portrays a side view of one embodiment of the present invention.

FIG. 4 demonstrates a functional block diagram of a portion of theelements of the present invention.

FIG. 5 depicts a flow chart of a process of an embodiment of the presentinvention.

FIGS. 6A-6C illustrate the possible output of a detector array.

DETAILED DESCRIPTION OF THE INVENTION

The present invention disclosed herein involves a device for use with ameter, where the meter is capable of sensing and measuring flow, wherethe flow under consideration includes electrical flow, gas flow, andfluid flow such as water and other liquids. With reference to FIG. 3,one embodiment of a remote terminal unit 30 of the present invention isshown in a side view. The remote terminal unit (RTU) 30 comprises anelectrical circuit (disclosed later herein in more detail), preferablyformed on a first and second circuit board (31, 32). The first circuitboard 31 is generally horizontal whereas the second circuit board 32 isgenerally vertical. A series of electrically conducting wires 38 can beincluded to conduct electrical current between the first and secondcircuit board (31, 32) as well as provide structural connect the firstand second circuit boards (31, 32).

Among the components of the RTU 30 is at least one source ofelectromagnetic radiation, such as a light emitting diode (LED) 34.Preferably the RTU 30 is equipped with three LEDs 34. Disposed on thesecond circuit board 32 proximate to the LED 34 is a detector array 33,such as a charge coupled device. The function of the detector array 33is to receive optical images, such as light, and convert the image intoan electrical signal.

The present invention includes a rotating wheel 20 that rotates inresponse to the amount of flow being sensed by the meter (not shown).Producing rotation of the rotating wheel 20 relative to the flow beingsensed by the meter is well within the capabilities of those skilled inthe art. In one example however, in situations where the presentinvention is used in an electrical meter, the rotating wheel 20 could bemotivated by a motor driven by the electricity passing through themeter, thereby providing a direct correlation of the flow passingthrough the meter and the rotational rate of the rotating wheel 20. Astripe 22 should be provided onto the outer surface of the rotatingwheel 20, where the stripe 22 is comprised of a material capable ofabsorbing electromagnetic radiation; where the electromagnetic radiationincludes light produced by the LED's 34. Further, the remaining outersurface of the rotating wheel 20 should be generally reflective.

With reference now to FIG. 4, the processor 54 of an embodiment of thepresent invention is shown with a power line carrier (PLC) 52 and apower supply 62. The power supply 62 is shown connected to two sourcesof 120 VAC power (70, 72) or one source of 240 VAC power, where thepower supply 62 converts this power into electrical power having theappropriate voltage and current useable by the processor 54. In additionto providing appropriate power for the processor 54, the power supply 62also provides 5 VDC 64, a ground connection 66, and 12 VDC 68.

The PLC 52 can include a central terminal unit (not shown) that acts asa receiving unit for receiving data packets from multiple processors 54.A central terminal unit (CTU) is a device that stores meter usage datathat can be accessed to determine the amount of flow measured by themeter. For example, the data within the CTU can be transmitted to autility base station for usage determination via wireless transmission,or via a line such as an electrical supply line. While the CTU can beconnected to an electrical supply line, the data it transmits via thesupply line can include electrical usage, water usage, or gas usage. Thedata packets can be analyzed for flow usage data as well as for testing,tampering, and possible component failures. The processor 54 is incommunication with a non-volatile memory 56 capable of storing the datapackets such that the data packets can be retrievable should theprocessor 54 lose power. Also connected to the processor 54 is a masterclear and memory reset 60 capable of clearing all memory within the RTU30, including the non-volatile memory 56 or simply resetting memorywithin the RTU.

In operation, the RTU 30 should be disposed proximate to the rotatingwheel 20 such that the light produced by the LED's 34 is capable ofreaching the rotating wheel 20 and being reflected back to the RTU 30.Moreover, the reflection from the rotating wheel 20 should be ofsufficient magnitude to be registered by the detector array 33. As therotating wheel 20 rotates in response to the sensed flow, the lightreflected from the reflecting surface of the rotating wheel 20 andsubsequently received by the detector array 33, will result in a “0” orlow output signal emanating from the detector array 33. In contrast, ahigh or positive output signal is produced by the detector array 33 whenno reflected light is directed onto it from the rotating wheel 20. Thedetector array 33 will experience no reflected light during the time thelight absorbing painted strip 22 rotates past the LEDs 34 and thedetector array 33—and thus a high or positive output signal will then begenerated by the detector array 33. Recording the number of high orpositive output signals produced by the detector array 33 translatesinto the number of revolutions experienced by the rotating wheel 20during the time the RTU 30 is in operation. As is well known, the numberof revolutions of the rotating wheel 20 can be directly correlated tothe amount of flow sensed by the meter.

One of the advantages of using a detector array 30 with a flow meter isthat the measurement of the meter will not be affected by theintroduction of light from sources other than the LEDs 34. Additionaladvantages of the present invention include the ability to ascertain theangular direction of rotation of the rotating wheel 20. As previouslydescribed, possible tampering with the meter can be determined byknowing the rotational direction of the rotating wheel 20.

Referring now to FIGS. 6 a through 6 c, a more specific description ofone embodiment of the present invention is shown. This series of figuresdemonstrates the relationship between the light reflected by therotating wheel 20 (or absorbed by the painted strip 22) and the outputsignal generated by the detector array 33. FIGS. 6 a through 6 c alsoillustrate additional detail regarding the detector array 33. Forexample, while the detector array 33 can comprise a single pixel element44 capable of receiving light and creating a corresponding signal, it isinstead preferred that it include a series of pixel elements 44, such ascan be found in a TSL201 1×64 array charge coupled device. Forsimplicity, only the first 11 and last 11 pixel elements 44 of theseries are shown in FIGS. 6 a through 6 c; these two series of pixelelements 44 are referred to herein as the first series 40 and the secondseries 42. FIGS. 6 a through 6 c illustrate the relative location of therotating wheel 20 with its associated painted strip 22 in relation tothe first and second series (40, 42). These figures also include theoutput signals (46 a-46 c) generated by the detector array 33 inresponse to the location and proximity of the painted strip 22.

With reference now to FIG. 6 a, a portion of the rotating wheel 20 a isshown adjacent the detector array 33. It should be noted that theportion of the rotating wheel 20 a of FIG. 6 a does not include thepainted strip 22, thus all of the light directed onto the rotating wheel20 by the electromagnetic radiation source should be reflected back ontothe entire detector array, and thus onto the first and second series(40, 42). As discussed above, since light is being received andregistered by both the first and second series (40, 42) of the detectorarray 33, the corresponding output signal 46 a will be in a “0” or lowstate.

FIG. 6 b portrays operation of an embodiment of the present inventionwhen the portion of the rotating wheel 20 b adjacent the detector array33 includes the painted strip 22. Here the painted strip 22 is shownfacing the first series 40, thereby absorbing the light directed fromthe electromagnetic radiation source and preventing light reflectiononto the first series 40. As such, the output-signal 46 b emanating fromthe pixel elements 44 comprising the first series 40 will register apositive or high reading. With reference to FIG. 6 c, the rotating wheel20 has rotated such that the painted strip 22 on the segment of therotating wheel 20 c adjacent the detector array 33 is aligned with thesecond series 42. Similarly the presence of the painted strip 22preventing reflective light from reaching the second series 42, which inturn causes the pixel elements comprising the second series 42 to havean output signal 46 c that is positive or high.

Analyzing the output signals (46 b, 46 c) of FIGS. 6 b and 6 a revealsthat passing the painted strip 22 past the detector array 33 can producea “ripple” across the output signals (46 b, 46 c). One of the advantagesof using an array of pixel elements instead of a pixel element is thatthe rotational direction of the rotating wheel 20 can be determined byevaluating the sequence of pixel elements having a high or positiveoutput signal. For example, if typical rotation of the rotating wheel 20resulted in the painted strip 22 exciting the first pixel elements 46before the remaining pixel elements 44, but instead the last pixelelement 48 were excited first, it could easily be determined that therotating wheel 20 was rotating opposite to its normal rotation. Sinceopposite rotation of the rotating wheel can be evidence of metertampering, quick detection of possible tampering can be obtained withthe present invention.

A processor 54 can be included with the present invention for thecontrol, data checking, data storage, and data transmission tasks. Thedata transmissible by the processor 54 includes data packets havingimbedded within the packets values representing energy sensed by themeter. As will be described in more detail below, the data packetstransmissible by the processor 54 also include data providinginformation as to the test mode, tamper, and power failure. In oneexemplary example the processor 54 can be a PIC16C622, where theprocessor 54 is controllable by firmware. FIG. 5 includes a flowchartdescribing firmware for use by one embodiment of the present invention.

Energizing the circuit containing the process allows the processor tostart 100 and begin the initialization 102 of the processor and theassociated circuit. After the initialization step 102, a query is madeif the test mode 104 should occur, if so the wheel count will be set tozero and stored in erasable memory included with the circuit 106. Thewheel count is the count of the actual number of times the wheel hasrotated, the blink count is a number that is programmed into the logicof the present invention. If it is determined that the test mode 104should not be done, the wheel count presently in erasable memory will beloaded and the blink count will be set to one 108. A command to starttimer 110 is initiated after each of steps 106 and 108, afterwards acommand is made to blink the LEDs 34 three times on and off 112. Afterthe blink command 112 the value of the blink count is reduced by one 114and the memory is queried for a blink count of zero 116. If the blinkcount is not zero, the process returns to step 112, if the blink countis zero, a query is made to see if the processor is in test mode 132. Ifthe processor is in test mode 132, the new state test mode bit is set134, if not, a query is made if tamper to the RTU 30 has occurred 136.Detecting tamper of the RTU 30 or associated meter hardware can be donethis by looking at the progression of data previously transmitted by theprocessor. If tamper is detected, the processor firmware can direct theprocess to set a new state tamper bit 138, if no tamper is detected aquery is made to determine if a power failure has occurred 140. If apower failure if determined to have occurred, the processor can bedirected to set a new state power fail bit 142. If no power failure isdetected, the count of the data packet can be stored into erasablememory 144, such as an erasable programmable read only memory. Step 144also can include a command to provide power to the LEDs 34. After steps142 and 144 a query is made determining if a valid wheel turn hasoccurred 146, i.e. in the proper direction of rotation. If a valid wheelcount is detected, a new state count bit is set 148, a query is made tosee if any state bits have been set 150—after step 148, the logicprocess directs the processor to step 150. If state bits have been set,then a value of one (or high value) is established for the state value152, otherwise a value of zero (or low value).

The state value (either 0 or 1) is returned and evaluated to determineif a change has occurred in the value of the state, if the value of thestate has changed the value, the data packet representative of the flowsensed by the meter is sent to a central terminal unit (not shown) 120,if not the logic process returns to step 132.

How often the data packets are sent can be based on programmed commandsor on operational upset conditions. For example, the time frequency ofsending the data packets from the processor to the CTU can be based onthe wheel count, or upon the change of state of a data bit that canindicate an upset condition. Upset conditions can include tamper, powerfail, or if the processor 54 is in test mode. An advantage of theflexibility of when the data packets are sent is realized when a problemwith the meter, such as tamper or power failure, can be detected soonafter this data is registered by the processor.

In instances where the present invention is used in conjunction with anelectrical meter, power for the RTU 30 can be take directed from theelectrical power supply on which the meter is located. The power supplycan be either 240 VAC and connected to each of the primary electricallegs; or can be 120 VAC by connecting between one of the primaryelectrical legs and the common ground. When the power supplied to theRTU 30 is in the form of alternating current, a full wave rectifier canbe included with the present invention, further a low voltage regulatorcan also be included for maintaining a constant low voltage for theassociated logic circuits.

The present invention described herein, therefore, is well adapted tocarry out the objects and attain the ends and advantages mentioned, aswell as others inherent therein. While a presently preferred embodimentof the invention has been given for purposes of disclosure, numerouschanges exist in the details of procedures for accomplishing the desiredresults. Such modifications will readily suggest themselves to thoseskilled in the art, and are intended to be encompassed within the spiritof the present invention disclosed herein and the scope of the appendedclaims.

1. A device for use with a meter, wherein the meter comprises a rotatingwheel rotate able in response to a flow sensed by the electric meter,wherein the rotating wheel includes markings on its outer surface,comprising: at least one electromagnetic radiation source capable ofemitting electromagnetic radiation onto the rotating wheel, where atleast a portion of the electromagnetic radiation emitted onto therotating wheel is reflected away from the rotating wheel and at least aportion of the electromagnetic radiation emitted onto the rotating wheelis absorbed by the rotating wheel; a detector array capable of receivingat least a portion of the electromagnetic radiation reflected from thewheel, wherein said detector array is capable of converting theelectromagnetic radiation it receives into a signal, where the signal isrepresentative of the flow sensed by the meter; and an analyzer inoperative cooperation with said detector array.
 2. The device of claim1, wherein said detector array comprises at least two separate arrays.3. The device of claim 2, wherein said two separate arrays are spacedapart.
 4. The device of claim 1, wherein said detector array comprisesat least one charge coupled device.
 5. The device of claim 1, whereinsaid source of electromagnetic radiation is a light emitting diode. 6.The device of claim 1, wherein the markings provide a surface capable ofabsorbing at least a portion of the electromagnetic radiation directedat the rotating wheel.
 7. The device of claim 1, wherein the meter isselected from the group consisting of electrical meters, gas meters, andwater meters.
 8. The device of claim 1, wherein the signal is selectedfrom the group consisting of an electrical signal, a pneumatic signal,and a wireless signal.
 9. A method of measuring flow with a meter havinga rotating wheel with markings provided on the rotating wheel, and agenerally reflective surface on the remaining surface on the rotatingwheel, wherein the rotating wheel is rotate able in response to the flowmonitored by the meter comprising: directing electromagnetic radiationat the rotating wheel, wherein at least a portion of the electromagneticradiation is absorbable by the rotating wheel and at least a portion ofthe electromagnetic radiation is reflect able from the rotating wheel;receiving at least a portion of the electromagnetic radiation reflectedfrom the rotating wheel; converting the electromagnetic radiationreceived into a signal; and analyzing said electrical signal therebydetermining the magnitude of the flow sensed by the meter.
 10. Themethod of claim 9 further comprising absorbing at least a portion of theelectro-magnetic radiation directed at the with the portion of therotating wheel having the markings and reflecting at least a portion ofthe electromagnetic radiation directed at the rotating wheel with thereflective surface of the rotating wheel.
 11. The method of claim 10,wherein the combination of the rotation of the rotating wheel with thereflections of the electromagnetic radiation directed at the rotatingwheel interrupted by the passing of the electromagnetic radiationabsorbing markings in the path of the electro-magnetic radiationdirected at the rotating wheel creates a ripple while receiving at leasta portion of the electromagnetic radiation reflected from the rotatingwheel.
 12. The method of claim 11, wherein said ripple is representativeof the rotation of the rotating wheel, thereby also being representativeof the rate of flow sensed by the electrical meter.
 13. The method ofclaim 10 further comprising determining the direction of said ripplethereby determining the rotational direction of the rotating wheel. 14.The method of claim 9 further comprising using a detector array toreceive at least a portion of the electromagnetic radiation reflectedfrom the reflective surface of the rotating wheel.
 15. The method ofclaim 14, wherein said detector array is comprised of a charge coupleddevice.
 16. The method of claim 9, wherein the source of theelectromagnetic radiation is at least one light emitting diode.
 17. Themethod of claim 9, wherein the meter is selected from the groupconsisting of an electrical meter, a gas meter, and a water meter. 18.The method of claim 9, wherein the signal produced is selected from thegroup consisting of an electrical signal, a pneumatic signal, and awireless signal.
 19. A method of measuring flow to a user comprising:Sensing flow to the user; Producing data representative of the sensedflow; and Forwarding said data to the provider of the flow.
 20. Themethod of claim 19 further comprising forwarding said data to a centralprocessing unit then forwarding the data to the provider of the flow.21. The method of claim 20 further comprising storing the data withinsaid central processing unit.
 22. The method of claim 19 wherein saiddata is forwarded based on a preset time frequency.
 23. The method ofclaim 19 wherein said data is forwarded based on an operational upsetcondition.